Transcript Climate Ppt - Newberry Life Science

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Weather: The state of the
atmosphere at a given time
and place, with respect to
variables such as temperature,
moisture, wind velocity and
direction, barometric pressure,
cloud cover
Climate: The meteorological
conditions, including
temperature, precipitation,
and wind, that characteristically
prevail in a particular region
over extended periods of time.
Things That Affect Climate
1.
2.
3.
4.
5.
6.
7.
8.
Air Pressure
Albedo
Altitude
Angle of Sunlight
Clouds
Distance to Ocean
Fronts
Greenhouse Effect
9.
10.
11.
12.
13.
14.
Heat
Land Changes
Latitude
Humidity
Mountain Ranges
Wind Patterns
Air Pressure
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99% of the mass of Earth’s atmosphere
is within 20 miles.
Gravity causes higher layers to exert
pressure on lower levels
Air pressure decreases with altitude
Air Pressure
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Cool air is more dense and therefore
heavier
Warm air is less dense and therefore
lighter
Because of this, warm air usually
rises above cool air
Air Pressure
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When cool air is sinking and pressed
to the ground, this creates an area of
high pressure. Associated with dry
and clear weather.
When warm air rises, this creates an
area of low pressure. Associated with
wet, cloudy weather.
Albedo
Effect
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- Oceans have low
albedo
-Land has
moderate albedo
- Ice and snow
have high albedo
Altitude
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For every 1,000 feet rise in
elevation, there is a 3 degree
Fahrenheit drop in temperature.
Angle of Sunlight
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What causes the seasons?
The tilt of the Earth’s axis!
Clouds
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Clouds are water vapor
As warm air rises, it begins to
cool.
As the air cools, the molecules will
slow down, turning water vapor
into liquid water (condensation)
Distance to Ocean
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Oceans moderate temperatures of
land close by
Changes in temperatures are more
extreme in the center of
continents
Fronts
- the boundary between two air
masses with different
temperatures and densities.
 Dramatic changes in weather
occur along a front
Warm Front
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The boundary between
an advancing warm air
mass and the cooler one
its replacing
• produces many layers
of clouds at different
altitudes
• leads to rainfall and
days of cloudy skies
Warm air = always
rises, less dense than
cold air
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The leading edge
of an advancing
mass of cold air
• produces
thunderheads
• leads to high
surface winds
and T-storms
• cooler
temperatures
and clear skies
Cold Front
Greenhouse Effect
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Without greenhouse gases, Earth
would be inhabitable because it
would be too cold
Heat: Solar Energy (Convection)
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Heat is transferred
from surplus to
deficit: equator to
poles
Distributes heat
and moisture
How is heat transferred??
Through Air and Water Circulation
Easterlies
(from the east)
Westerlies
(from the west)
60°N
Northeast
tradewinds
30°N
(Doldrums)
equator
30°S
60°S
Initial pattern of
air circulation
Fig. 6.6b, p. 125
Southeast
tradewinds
Westerlies
Easterlies
Deflections in the
paths of air flow
near the earth’s surface
Fig. 6.8, p. 126
Latitude
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Less solar radiation at higher latitudes.
Gainesville should be a desert.
Land Changes
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Urbanization
Deforestation
Humidity
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Moisture content of air
Lack of humidity = desert
Increase humidity = tropical
rainforest
Dew point: temperature at which
condensation takes place
Relative Humidity
If the relative humidity is 30%, the air
temperature is 60 degrees F, and the
air temperature rises to 90 degrees F
without any additional moisture
entering the atmosphere, will relative
humidity increase or decrease?
Mountains: Rain Shadow Effect
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Winds pick up moisture from oceans. When that
air mass reaches a mountain, it must rise to get
over the mountain. It cools as it rises, releasing
most of its moisture.
Windward side of the mountain is wet; Leeward
side of the mountain is dry
Wind Patterns
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Air always flows from an area of high
pressure to low pressure
CORIOLIS EFFECT
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Caused by the Earth’s rotation
Air rotates counterclokwise in the
northern hemisphere
Air rotates clockwise in the southern
hemisphere
CORIOLIS EFFECT
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The reason why cyclones and hurricanes
rotate counterclockwise in the northern
hemisphere and clockwise in the southern
hemisphere.
Causes patterns of air movement
(prevailing winds)
Causes patterns of ocean currents
https://www.youtube.com/watch?v=i2mec3v
geaI
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PREVAILING WINDS
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Responsible for patterns of heat and
moisture flow
OCEAN CURRENTS
Warm vs. Cold
Cold water is heavier and sinks to the
bottom
• Warm water is lighter and flows along
the top
http://www.youtube.com/watch?v=w_8
mw1HYFg&safety_mode=true&persist_safety
_mode=1&safe=active
Difference in water density due to
temperature and salinity concentrations
•
Things That Effect Climate
Most important
1. Temperature
2. Precipitation
Climate
is
the average weather patterns for an area
Over a long period of time
(30 - 1,000,000 years).
It is determined by
Average Precipitation
and
Average Temperature
which are influenced by
latitude
altitude
ocean currents
and affects
where people live
how people live
what they
grow and eat
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Violent storms
called tornadoes
(form over land) and
tropical cyclones
(form over warm
ocean waters)
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Tropical cyclones
are hurricanes in
the Atlantic and
typhoons in the
Pacific Ocean
Weather Extremes
Tornados
ENSO = El Nino Southern
Oscillation
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Normal trade winds blow from east to west and
cause upwellings, nutrient rich bottom water is
pushed to surface. Good Fishing!
ENSO reverses the direction of the trade winds (now from W ->
E) which depresses upwellings. Decreases biodiversity.
El Nino
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Every 2-7 years
Sharp decline in fishes because no uprising of nutrient-rich
cold water along South American coast.
Alters weather of 2/3 of the globe
Land along Pacific and Indian Oceans effected greatly
U.S.- fewer or weaker Atlantic hurricanes and drought in
the southwest
Thermocline: rapid change in temperature in body of water
El Nino causes the thermocline to fall deeper into the ocean
La Nina
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Trade winds blow even harder from east
to west.
Effects are opposite
Hurricanes in Atlantic are stronger